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The Japanese Freighter (presumably) Shoan Maru is included in Saipan's Maritime Heritage Trail, and I hope to freedive this wreck too in Tanapag Lagoon with some other World War II wrecks.

The wreck is locally referred to as the Chinsen, or simply as "the shipwreck", this wreck is a Japanese merchant vessel tentatively identified in 1990 as Shoan Maru. Nearly two dozen merchant vessels, including Shoan Maru, were sunk in Tanapag Lagoon or in deep waters surrounding Saipan during World War II. Commissioned during the war years, they served as auxiliary submarine chasers, guard boats, and transports. Many ships were used as transports during the inter-war years and later requisitioned for use were either purchased from foreign builders or seized during World War I.

The list of typical transports provided in warships of the Imperial Japanese Navy, 1869-1945 includes ships built in Scotland, Germany, and England. These ships were generally fitted with vertical tripleexpansion steam engines and water tube boilers, a good time-marker for pre-war build. Very Little information ha come to light regarding the story of Shoan Maru. It is referenced only as a standard steamer transport of 5,624 gross registered tons built in 1937 and requisitioned for use during the war years. As such, it was pupose-built for wartime use.

According to records of U.S. submarine attacks, Shoan Maru was torpedoed on 27 January 1943 west of Rota. It was damaged but, due to defective torpedoes, the ship did not sink and was later towed to Saipan for repair or salvage. At the time of the submarine attack it was reportedly carrying conscripted Korean soldiers which have since been commemorated on the shipwreck site with a monument. The ship was still grounded in Tanapag Lagoon more than a year later, when it was damaged beyond repair during airborne raids from the Task Force 58 carriers Essex and Yorktown.

During the post-war cleanup of the harbor, the ship was cut down to the waterline because it was considered a navigation hazard. Between 1949-1962, the Central Intelligence Agency (CIA) had control over much of the northern half of Saipan. Under the cover of the U.S. Navy, a facility known as the Naval Technical Training Unit (NTTU) provided training in intelligence tradecraft, communications, counter-intelligence, psychological warfare techniques and sabotage. The remains of Shoan Maru were reportedly used for explosives training by the NTTU.

The disarticulated remains of this Japanese freighter lie in 10m of water on a sandy bottom. The ship lies on its starboard side and little remains intact, except for a section of the bow. Although most of the ship has been damaged due to the effects of explosives and salvage efforts, the major elements such as the engines, boilers, steering gear, and superstructure are located in the general area of their original positions. At one time, a few bicycles were still visible in the cargo areas, however, these have not been seen for years. The overall length of Shoan Maru was approximately 125m, but the wreck as it appears on the seabed is scattered over an area of approximately 274m. This is likely due to salvage and explosion efforts.

Marine life on the wreck is abundant and changes from season to season. The sheer size of the surviving structure attracts greater numbers of larger fish species. Predatory red bass patrol the edge of the wreck, and also school at the bow in heavier currents. Shoals of daisy parrotfish scour the hull for algae. Schools of yellowfin goatfish shelter on the leeward side, often associating with bluestripe snapper, whose colouring they resemble. Solitary Chinese trumpetfish can also be found on the on the leeward side of the wreck.

- I'm making the last reservations for the Philippines & Micronesia project at the moment.

Jean Dar

One worldOne lifeOne moment

I have a passion for travelling, having visited multiple countries on six continents for longer or shorter periods throughout the years. My interests include a wide array of areas, spanning from creativity to scientific matters and culinary delights to physiology and beyond.

I speak fluently English and Swedish, and at best I do fairly well in Spanish, and less well in French.